THE MANUFACTURE AND USE OF STARTERS FOR THE DAIRY INDUSTRY: CHARACTERISTICS AND USE OF STARTERS FOR THE MANUFACTURE OF YOGHURT, COTTAGE CHEESE, CULTURED BUTTERMILK AND OTHER FERMENTED PRODUCTS

This paper details the characteristics of a good starter culture, and then considers aspects of each characteristic which determine the selection of suitable starters for 'fresh' short shelf-life fermented dairy products. Within the context of each product, procedures are outlined for the handling of cultures in order to obtain optimum performance during manufacture. Quality control tests necessary for the maintenance of starter performance are given. The variety and number of products included in the group will ensure a continuing interest in the properties of starters used for their production.     

MANUFACTURE OF STARTERS: STARTER MANUFACTURE AT INDIVIDUAL CHEESE FACTORIES

Cheese production on a modern scale depends largely on reliable starters which are required to produce uniform acidity during long working hours, be consistent from day to day, and able to work in changeable media for a variety of products under different techniques. Sufficient starters are available, selected to ensure that they have these qualities, but care in handling from day to day, and during the scaling up in quantity, is the most important factor in the practical world of cheesemaking. Some of the main reasons for poor starter behaviour are set out, and a number of alternative systems for maintaining their performance. Care begins in the laboratory, and attention to detail at this stage must be followed by the same vigilance during bulk starter production. One of the most effective methods of achieving overall reliability is described.     

干酪成熟过程发酵剂的作用及快速成熟的研究进展

干酪的成熟过程,是在添加酶及各种微生物的协同作用下完成的.干酪中的微生物作用也包括人为添加发酵剂的作用.本文综述了干酪生产过程中发酵剂的使用和成熟过程所起的作用,主要有酸化、改善质构、形成风味物质.此外,本文也讨论了干酪的成熟机制,综述了目前用于促进干酪成熟所使用的一些方法和技术以及对它们的最新研究进展.     

MANUFACTURE OF STARTERS: THE USE OF COMMERCIALLY AVAILABLE CONCENTRATED STARTERS

The paper describes the development of cultures for the dairy industry by the Marschall Dairy Laboratory, which was later to become the Marschall Division of Miles Laboratories, from 4 oz mother cultures distributed in 1906 without refrigeration to 'Superstarts', Marschall's concentrated frozen direct-to-the-vat cultures. The paper also describes the first successful large-scale trial in the UK with direct-to-the-vat cultures.     

THE USE OF CONCENTRATED SINGLE STRAIN CHEESE STARTERS IN SCOTLAND

Recent success using concentrated single strain starters in Scotland is based on continuing research work mainly by the New Zealand Dairy Research Institute. The Institute has isolated groups of 'phage unrelated single strain starters capable of producing good flavoured Cheddar cheese. These starters were concentrated and used to produce cheese on automated and mechanized equipment. The results are evaluated. Reliable acid production from the same starters used in refilled vats depends on adequate intermediate sanitation to control the phage levels to a predetermined level and the regular replacement of stock cultures.     

THE ECONOMIC USE OF DETERGENTS AND SANITIZERS IN THE DAIRY INDUSTRY

The various types of detergents, detergent sanitizers and sanitizers available on the market are first discussed with specific reference to the advantages and disadvantages of certain components. The cleaning operation is then broken down into various economic factors. The use of water and reclaimed water is detailed with hints on water-saving techniques. The energy factor is discussed with the pros and cons of hot versus cold cleaning. Concentrations and the automatic control of solutions are also covered, together with correct methods of detergent application and the reclaiming and re-use of detergent solutions. Finally, the problems of effluent discharge are covered and two forms of treatment outlined.     

MANUFACTURE OF STARTERS: PRODUCTION OF FROZEN CONCENTRATED CHEESE STARTERS BY DIFFUSION CULTURE

Diffusion culture allows the production of concentrated cheese starter without centrifugation principally by removing inhibitory lactate from fermentations. Laboratory scale fermentation systems are described which remove lactate via a diffusion membrane. Single and mixed strain cultures were grown to concentrations of 10¹¹/ml in an enzyme digest of skimmed milk supplemented with yeast extract. The present stage system is capable of producing at least half the annual bulk starter requirements of a creamery processing 100,000 gal of milk/day. Concentrated cultures were harvested in hypodermic syringes and as frozen granules. Concentrates were tested for purity and activity and suitable ones used in a commercial cheesemaking trial which produced a high proportion of extra selected grade Cheddar cheese.     

THE EFFICIENT USE OF LABOUR IN THE DAIRY INDUSTRY

The complex nature of the work force of the dairy industry and the problems in promoting efficiency and effectiveness are reviewed and the techniques of work study and work management evaluated. The contribution of a participative management approach involving all members of the work force is outlined and the need for the maintenance of a consistent personnel policy stressed. The problems of recruitment and the need for encouragement and training of school leavers and graduates is examined and the importance of regular appraisals as an integral part of their development emphasized ( Editor's summary ).     

MANUFACTURE OF STARTERS: THE MANUFACTURE OF STARTERS BY BATCH FERMENTATION AND CENTRIFUGATION TO PRODUCE CONCENTRATES

The advantages of the concentrated system over conventional methods, as well as the disadvantages, are assessed. The batch method of concentrate production requiring a pure culture grown to a high total level is discussed and tables given showing total cell count and yield. The necessity for quality control of the concentrate to ensure meeting standards regarding species, strain type, cell numbers and acid producing activity is stressed. The design of process plant equipment is described in detail and the layout of the system evaluated. ( Editor's summary. )     

RECENT DEVELOPMENTS IN YOGHURT STARTERS: THE USE OF MILK CONCENTRATED BY REVERSE OSMOSIS FOR THE MANUFACTURE OF YOGHURT*

The preparation of yoghurt from milk concentrated by reverse osmosis to 12.5 and 15.0 per cent TS was compared with that from milk adjusted to comparable concentrations by the addition of skim milk powder. Culture growth, acid production, acetaldehyde production, viscosity and flavour scores of yoghurt prepared from the reverse osmosis concentrates were at least equal to those of yoghurt prepared from conventionally concentrated milk, suggesting that the former constitutes a suitable yoghurt base.     

USE OF MILK CONCENTRATED BY ULTRAFILTRATION FOR MAKING HARD CHEESE,SOFT CHEESE AND YOGHURT*

Whole milk was concentrated by a factor of two by ultrafiltration. It was used directly for making Cheddar and Cheshire cheese, an unripened soft cheese of the Coulommier type, and yoghurt. The yields of hard cheese from the concentrated milk were the same as those from normal whole milk. The cheeses were acceptable though the flavour was milder than that of good quality Cheddar and Cheshire cheese. Medium fat soft cheeses were made from the concentrated milk. The yield of cheese was 41 per cent greater than that made from normal whole milk and the making time was half that of the normal process. The cheeses were consumed fresh or stored in deep freeze. For making yoghurt, the usual reinforcement with skim milk powder was not necessary as the concentrated milk had a high total solids content, nor was it necessary to homogenize the mix. The yoghurt contained 21 per cent total solids and was a very acceptable product.